This invention relates generally to case erecting machines, and particularly to machines, apparatuses and methods for erecting cases stored in flattened positions within one or more storage magazines.
Machines have heretofore been devised for erecting cases stored in flattened position for subsequent packing of goods. U.S. Pat. Nos. 3,626,661, 3,637,129 and 3,763,750, which patents are assigned to the assignee of the present invention, exemplify such machines. In general, these machines serve to open the flattened cases and to fold in and secure together the bottom case flaps. Subsequently, the cases are packed with goods and the top panels folded and sealed.
Though case erecting machines of the prior art have been successfully employed in automatically erecting flattened cases for packaging, they have not been free of problems. For example, where the cases are stored in upright positions for one at a time dispensing, it is continuously necessary to present an end member case at an extraction station at one end of the storage magazine where it may be gripped by extracting mechanisms. Some machines have employed continuously rotating drive shafts or augers upon which the case blanks are suported and rotated for continuously urging them towards the magazine end extraction stations. This constant rotation of augers beneath the cases, however, often deforms the bottom edges of the cases through constant rubbing action. The continuous rotation of the shafts also consumes power needlessly when case movement is not required. A dilemma is also presented here in providing positive stop means against which end member cases may be urged where an extraction exit must also be located.
In addition to the just mentioned difficulties encountered in extracting end member cases one at a time from storage magazines, the box erecting mechansims of prior art machines have met the relatively limited success in squaring the corners of the cases during the erecting process. For example, in initially opening the flattened, usually cardboard cases the wall hinges tend to "remember" their former orientations. This memory causes the walls to tend to return somewhat toward their previous orientation after having been physically opened. Thus, where the sides of the cases are brought into right angle corner hinged positions means must ordinarily be provided for maintaining this angle or else the box sides will self-assume an acute or obtuse angle in their tendency to return to their previous flattened position.
Another squaring problem is presented in the process of glueing together bottom panel members of the cases during erection. As the cases proceed through the various operative stations within the machine they typically move in a generally horizontal direction. At one point in their travel at least one of their bottom panels is passed over apparatus for applying an adhesive coating to the bottom thereof. Once the case is urged out of this station another bottom panel member is folded in upon the glue bearing surface of the other bottom panel. As the two panel members come together one panel member will tend to slip over the surface of the other panel member due to the frictional drag imparted thereto by the overall movement of the case in a traverse direction with respect to that of the closing panels. This drag tends to throw the sides of the cases out of square.
Yet another squaring problem is presented in the panel compression station where the glued bottom panels are compressed to form a firm seal. Typically, in compressing the bottom panels the cases are positioned upon an anvil and a mandrel is then passed into the container through the open top thereof and onto the upper surface of the upper case bottom panel and end flaps whereby the two case bottom panels are compressed between the anvil and mandrel. At this station the movement of the case through the machine has typically been arrested in order to avoid having to mount the mandrel and anvil thereunder for horizontal movement in company with the cases. In accomplishing this the cases are typically urged by flight bars or the like up against a stop whereupon the flight bars break contact with the cases. However, once this positive contact is broken the cases placed against the stops are free to move out of square since there is no continuing force being applied to press the cases firmly against the stops. Should the mandrel then descend towards the interior of the case it may contact the top thereof and crush the case rather than passing into the interior thereof. Where the width of the mandrel is reduced in order to insure that clean passage will be achieved all portions of the bottom panels will not be encountered by the descending mandrel and thus not subjected to uniform compression.
Accordingly, it is a general object of the present invention to provide an improved case erecting machine.
More specifically, it is an object of the present invention to provide improved methods and apparatuses for dispensing case blanks one at a time from a stack of flattened cases juxtaposed in upright positions in one or more case magazines.
Another object of the invention is to provide improved apparatus for simultaneously dispensing pairs of cases stored in flattened positions in a plurality of magazines.
Another object of the invention is to provide improved methods and apparatuses for opening flattened cases having one side and one end disposed along a first plane and an opposite side and end disposed along a second plane closely parallelling the first plane.
Another object of the invention is to provide improved methods and apparatuses for securing bottom panel members of cases together.
Another object of the invention is to provide improved apparatuses for squaring the sides of cases being moved along a preselected path within a case erecting machine.
Another object of the invention is to provide a case errecting machine whose moving components generally move at uniform velocities thereby minimizing or completely avoiding intermittent motions.
Yet another object of the invention is to provide a case erecting machine requiring minimal use of hydraulic or air cylinders and timing controls for such cylinders.